Question

In my database, v1 field is nullable field. but I define 0 (default) if the value is null.

public decimal? v1 {
  get {
    return this._v1; 
  }
  set {
    this._v1 = value ?? 0M;
  }
}

so now, the v1 is not nullable variable anymore.

but I can not do this,

decimal v2 = v1;

The error message say, Cannot implicitly convert type ‘decimal?’ to ‘decimal’.

In this case, Do I have to convert to decimal, like this?

decimal v2 = Convert.ToDecimal(v1);

It very annoying job. and codes are look dirty too.

Anyone know better solution? please advice me.

Answer 1

No you don’t have to convert the decimal?, you have access to the underlying value from the Nullable type e.g.

decimal v2 = v1.Value;

Assigning a default value to a Nullable type does not make it non-nullable, it just means it has a value. Nullable types have a HasValue property which helps you determine this.

Just for the record, I wouldn’t recommend defaulting the value to 0 it would probably make more sense letting it default to null considering it can indeed be null. If you need to have a default value in your app you will probably want to use the GetValueOrDefault method e.g.

decimal v2 = v1.GetValueOrDefault(0m);